Advanced Sensory Hardware for Intelligent Eye-Machine Interfacing: from Wearables to Bionics

Eye-machine interfacing (EMI) is playing a critical role in enabling effective and immersive human-machine interaction (HMI), which is of significance in various fields related to the Internet of Things (IoT), including VR/AR, autonomous driving, brain-computer interface, robotics, biomedicine, etc. EMI is realized by various eye-interfaced technologies, from wearable eye-movement tracking and theranostic smart contact lenses to visual prosthetic implants and bionic eyes, where progress is being promoted by the rapid advancements in corresponding sensory technologies toward the vision of reduced size, weight, and power consumption (SWaP). Emerging functional materials, especially low-dimensional nanomaterials, are the key driving force in enabling flexible and transparent design, multimodal and intelligent sensing, and up-scaled, integrated processing in advanced EMI sensory hardware. In recognition of the importance of EMI and recent progress in its key sensory technologies, this article provides a critical review of the state-of-the-art EMI fundamentals, materials, and devices, highlighting the advanced functional nanomaterials-based progress in eye-tracking, healthcare, and visual prosthetics. Moreover, insights are provided, where flexible and transparent form factors, in-sensor computing architectures, and biomimetic communicating methods are envisioned, aiming at promoting elaborations on future wearable and bionic EMI applications toward optimized SWaP.